World No.13 Madison Keys became the latest player to pull out of this month's Australian Open.

A semifinalist in Melbourne in 2015 and 2022, Keys announced Thursday she will be sidelined with a shoulder injury. 

"This obviously isn’t the best news to start the tennis season, but I also know I’m making the right choice for my body," Keys said in a post on X, the platform formerly called Twitter.

Keys is the sixth player on the original main-draw list to withdraw from the Australian Open, following Irina-Camelia Begu, Caty McNally, Karolina Muchova, Lauren Davis and Petra Kvitova -- the last of whom recently announced that she is pregnant with her first child. 

Muchova, the 2023 Roland Garros runner-up, reached her first major final last spring but was forced to end her breakout season early as a result  of a recurring wrist problem.

After reaching the semifinals of the US Open, where she lost to eventual champion Coco Gauff, Muchova withdrew from events in Tokyo and Beijing, as well as the GNP Seguros WTA Finals Cancun -- having qualified for the year-end event for the first time. Despite her shortened year, she finished at a career-high ranking of No.8, which she reached after her exploits in New York.

"This isn’t my favorite thing to share especially at the start of a new season, but unfortunately the pain in a wrist came back in the middle of my tennis preparation," Muchova wrote on Dec. 28 in an Instagram post. "I therefore have to postpone the start of the season and fully heal my wrist first."

Muchova will be missing from the field in Melbourne for the second time in the last three years. She reached the semifinals of the Australian Open in 2021, upsetting then-World No.1 Ashleigh Barty along the way but also skipped the tournament in 2022 due to injury.

Both Keys and Muchova were also entered in the WTA 500 Adelaide International, which begins on Jan. 8.